Score-line structure

ABSTRACT

A score line impressed into a container wall to define a dispensing opening. The score line has a radius along at least one edge of the bottom wall thereof to insure that tearing of the strip takes place along a predetermined path and so that the lower, flat portion of the score line is removed to thereby preclude the formation of a thin, sharp fin and thus reduce the cut hazard around the dispensing opening.

llriited States i ate tit {72] inventor David C. O'Neill Sprinweld Township, Hamilton County, Ohio [211 App]. No. 837,532

[22] Filed June 30, 1969 [45] Patented Aug. 24, 1971 [73] Assignee The Proctw 8r Gamble Company Cincinnati, Ohio [54] SCORE-LINE STRUCTUM 4 Claims, 5 Drawing Figs.

220/54 1B6Sd 17/24 Field of Smrch 220/54, 27, 48

[56] References Cited UNITED STATES PATENTS 3,406,866 l0/l968 Jasper 220/54 3,244,315 4/1966 Taylor 220/54 Primary Examiner-George T. Hall Attorney-John V. Gorman ABSTRACT: A score line impressed into a container wall to define a dispensing opening. The score line has a radius along at least one edge of the bottom wall thereof to insure that tearing of the strip takes place along a predetermined path and so that the lower, flat portion of the score line is removed to thereby preclude the formation of a thin, sharp fin and thus reduce the cut hazard around the dispensing opening.

SCORE-LINE STRUCTURE BACKGROUND OF THE INVENTION This invention relates to containers having dispensing openings. More particularly, the invention relates to the provision of an improved score line to define a dispensing opening, the score line having at least one radius to ensure that tearing takes place along a predetermined path.

The use of score lines to define dispensing openings in metallic end walls of containers is well known. The cross section of the conventional score line resembles an inverted A trapezoid to conform with the configuration of the tool which is utilized to impress the score into the metallic wall. The

result is a narrow, straight section at the base of the score line and two sloping sidewalls which interconnect the base of the score line with the top surface of the end wall.

When the conventional score line is torn or severed to remove the portion of the end wall circumscribed by the score line and. thereby permit access into the container for withdrawing the contents therefrom, the tear usually takes place along one edge of the base of the score line since it is at either of those positions where the stress concentration is greatest and therefore where the rupture will occur. When such conventional score lines are employed on metallic container walls to define dispensing openings having a size large enough to permit the passage therethrough of a users hand to withdraw the product from the container, a significant cut hazard arises in that frequently the tear takes place at the edge adjacent the portion to be removed with the result that a sharp, ragged-edged fin results which projects into the dispensing opening-The resulting fin is a comparatively thin structure approaching a knifelike edge. It is an object of the present invention to obviate this difficulty.

SUMMARY OF THE INVENTION Briefly stated, in accordance with one aspect of the present invention, a score line is provided in a container wall to define a removable portion to provide a dispensing opening, the score line formed by a line of reduced thickness in the wall to facilitate the severance of the removable portion therefrom. The score line comprises a pair of oppositely directed oblique sidewalls interconnecting the top of the end wall of the container with a bottom wall parallel to the upper surface. One of the sidewalls and the bottom wall are joined by means of a radius to provide a smooth connection therebetween so that tearing of the score line takes place at a predetermined position at the intersection of the other sidewall and the bottom wall.

BRIEF DESCRIPTION OF THE DRAWING FIG. I shows an end wall ofa container having a removable portion defined by a score line to provide a dispensing opening.

FIG. 2 is an enlarged, fragmentary cross-sectional view taken along the line 2-2 illustrating the score line and its relationship with the side and end walls of the container.

FIG. 3 is an enlarged, fragmentary cross-sectional view showing the configuration of the score line of the present invention prior to severance.

FIG. 4 is an enlarged, fragmentary cross section showing the configuration of the score line of the present invent-ion after the score line has been ruptured to permit access to the interior of the container.

FIG. 5 is an enlarged, fragmentary cross section showing another embodiment of the score line of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, and particularly to FIG. 1 thereof, there is shown an end wall of a container (not shown) in which a score line 11 has been impressed and a pullremoval of the removable portion 13'of end wall 10. Endiwall 10 can be attached to sidewall/l4 by means of, for example, a

double seam bead l5 asshown more clearly in FIG. 2. The positioning of pull-tab 12 with respect to score line l1v is 1 described more fully in U.S.Pat. No. 3,366,270., issued Jan.

30, 1968, to NS. Khoury, the disclosure of which is hereby incorporated herein by reference. q

Although shown as being of circular configuration, end wall 10 of the container can take any desired form, such as, for example, oval or rectangular. Similarly, the dispensing opening can also be of any ,desired configurationsuch'a's those shown in U.S. Pat. No. 3,334,777, issued Aug. 8, I967, to G-.F.

Smyth, and U.S. Pat. No. 3,244,315, issued Apr. 5, 1966, to W. E. Taylor. E

The conventional score lines utilized to define the dispensing openings described in the above-mentioned patents are formed by a die of trapezoidal cross section which is impressed into the end wall to displace the metal thereof and providethe score line therein. The resulting score line has a lower wall, or base which is spaced from the outer surface of the end wall in which'the score line is impressed, and two sloping sidewalls which flareupwardly and outwardly from the base to the outer surface of the end wall. Generally, the end walls in which such score lines are impressed have a thickness of from about 5 to about 14 mils. When the end wall is formed from tinplated steel, commonly known in the can-making industry as pound TH tinplate, the thickness of such end walls is typically about 10 mils. However, when aluminum alloy is used to provide such end walls, the range of thickness of the end wall can be from 10 to 20 mils with 10.5 mils being a typical thickness.

In order to provide the desired ease of opening and also provide the resistance to rupture fromhandling and shipping loads imposed on the containers, the, normal minimum thickness at the point where the score line is impressed is 2 mils for tinplate end walls and is from 2.5 to 5 mils when aluminumalloy is used as the end wall material. This thickness of the flat section of the lowermost portion of the score line, the distance from the base of the score line to the inner surface of the end wall, is sometimes referred to in the industry as the residual and it is that thickness which principally determines the ease of removal of the end wall, depending upon the material utilized.

Thus, it can be seen that in conventional score lines of trapezoidal cross section there are in essence two stress concentration areas, each of which is positioned at an end of the base portion of the score line. It is impossible to predict along which of these stress concentration areas tearing will take place, and thus the sharp, ragged, fin-type edge frequently remains on the portion of the end wall forming the dispensing opening to provide a cut hazard to the user, particularly in those instances where the dispensing openings are so sized as to permit the passage of the users hand therethrough to withdraw the contents from the container.

The improved score line of the present invention is shown in cross section in FIG. 3. The score line is impressed into end wall 10 by means of a suitably shaped forming tool (not shown) which is forced into the end wall'to form a depression which comprises a base or bottom wall 16 parallel to upper surface 17 and lower surface 18 of end wall 10, a first sidewall 19, and a second sidewall 20. Sidewall 19 is obliquely positioned with respect to both bottom wall .16 of score line 11 and upper surface 17 of the end wall 10 and is provided to form a stress concentration area at the intersection 21 of sidewall 17. and bottom wall 16 of score line 11. The fact that a sharp corner is provided results in apredetermined line of weakness to permit initiation andpropagation of the tear.

Second sidewall 20 is provided at the other side of score line 11 and, like first sidewall 19, it is also obliquely positioned with'respect to upper surface 17 of end wall 10, but does not extend all the way to bottom wall 16. Instead, second sidewall 20 and bottom wall 16 are joined by a radius that is tangent to both designated R in FIGS. 3 and 4, forming a fillet in order to avoid the formation of a stress concentration area at that point. Since only a single stress concentration area is present, intersection 21, the tear will take place along that intersection and not along the radius R and thus the bottom wall 16 will be removed with removably portion 13, thereby reducing the cut hazard by presenting a more blunt edge at the dispensing opening.

In FIG. 4, score line 11 is shown after severance of removable portion 13 from end wall 10 and it can be seen that the finlike portion 22 is removed with removable portion 13. Thus the resulting dispensing opening is characterized by a relatively blunt edge defined by first sidewall 19 and edge portion 23 and the cut hazard is reduced.

Bottom wall 16 is preferably at least about I mil in width so that as the tool used to form the score line wears from prolonged used, the residual thickness r (see FIG. 3) is maintained for a longer period of time. Thus bottom wall 16 defines a web of uniform thickness with respect to lower surface 18 of end wall 10. Although bottom wall 16 could, in theory, be eliminated completely so that radius R interconnects the lower edge portion of first sidewall 19 with second sidewall 20, the sharp intersection between the radius and the first sidewall will quickly disappear due to wear of the forming tool, which will result in the formation of a radius at that point and also a larger residual, r, thereby increasing the force required to rupture the score line.

When the score-line configuration forming the basis of this invention is employed, radius R can range from 2 to up to 9 mils, and is preferably from 3 to mils. The upper limit of radius R is limited only by the thickness of end wall employed and the desired residual thickness 12. That radius can, in fact, extend all the way from bottom wall 16 to the upper surface 17 of end wall 10 and there need not be a straight second sidewall 20 as shown in FIG. 3 but it can take the form shown in FIG. 4, if desired, wherein one entire side of the score line is defined by radius R. In that instance the radius R is the same value as the depth of the score line from the upper surface 17 of end wall I0 to the bottom wall 16 of score line 1 I.

In addition to the above-described embodiment, the benefits of the present invention can also be obtained even if there is a radius at each lower corner of the score line at the respective ends of bottom wall 16 thereof as shown in FIG. 5. As shown, this variation is the same as the embodiment shown in FIG. 3 except the intersection 21 is replaced by radius R,. In

this embodiment it is only necessary to provide that one of the radii be greater than the other to insure that the tear takes place along the smallest radius. Thus, radius R: should be greater than radius R, to insure that tearing will take place in a plane which passes through radius R When so configured, it is preferred that radius R; range from 2 to 5 times greater in size than radius R While particular embodiments of the invention have been i1- lustrated and described, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention, and it is intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.

What is claimed is:

1. In a container having a removable portion to provide a dispensing opening in one end wall thereof, said removable portion defined by a score line forminga line of reduced thickness in said wall to facilitate severance of said removable portion from said wall and thereby provide said dispensing opening, the improvement comprising a score line having a first and second sidewall and a bottom wall, said bottom wall and said first sidewall being defined in cross section by straight lines, said first sidewall intersecting said bottom wall at an oblique angle forming a sharp corner therebetween, said bottom wall being generally parallel to the upper and lower surfaces of said end wall to define a web of uniform thickness said second sidewall intersecting the upper surface of said removable portion and being generally obliquely oriented therewith, the junction of said second sidewall and said bottom wall defined by a smooth curve tangent to said second sidewall and said bottom wall to provide a fillet joining said walls, whereby tearing along said score line will take place along the line of intersection of said first sidewall and said bottom wall, whereby removal of said removable portion includes the removal of said web of uniform thickness to thereby reduce the cut hazard when a user inserts his hand within said dispensing opening.

2. The container of claim 1 wherein said fillet joining said second wall and said bottom wall has a radius in the range from about 0.4 to about 4.5 times the thickness of said web.

3. The container of claim 2 wherein said radius ranges in size from 2 to 9 mils.

4. The container of claim 1 wherein said second sidewall is defined by said radius and extends from said bottom wall to the upper surface of said container wall. 

1. In a container having a removable portion to provide a dispensing opening in one end wall thereof, said removable portion defined by a score line forming a line of reduced thickness in said wall to facilitate severance of said removable portion from said wall and thereby provide said dispensing opening, the improvement comprising a score line having a first and second sidewall and a bottom wall, said bottom wall and said first sidewall being defined in cross section by straight lines, said first sidewall intersecting said bottom wall at an oblique angle forming a sharp corner therebetween, said bottom wall being generally parallel to the upper and lower surfaces of said end wall to define a web of uniform thickness, said second sidewall intersecting the upper surface of said removable portion and being generally obliquely oriented therewith, the junction of said second sidewall and said bottom wall defined by a smooth curve tangent to said second sidewall and said bottom wall to provide a fillet joining said walls, whereby tearing along said score line will take place along the line of intersection of said first sidewall and said bottom wall, whereby removal of said removable portion includes the removal of said web of uniform thickness to thereby reduce the cut hazard when a user inserts his hand within said dispensing opening.
 2. The container of claim 1 wherein said fillet joining said second wall and said bottom wall has a radius in the range from about 0.4 to about 4.5 times the thickness of said web.
 3. The container of claim 2 wherein said radius ranges in size from 2 to 9 mils.
 4. The container of claim 1 wherein said second sidewall is defined by said radius and extends from said bottom wall to the upper surface of said container wall. 